I want my Python [2.4.3] output numbers to have a certain format. Specifically, if the number is a terminating decimal with 6 significant digits, then output only 6 significant digits.
"A" shows how Python is writing the floats. "B" shows how I want them written. How can I make Python format my numbers in that way?
A:
10188469102.605597
5.5657188485
3.539
22.1522612479
0
15.9638450858
0.284024
7.58096703786
24.3469152383
B:
1.01885e+10
5.56572
3.539
22.1523
0
15.9638
0.284024
7.58097
24.3469
Burhan Khalid
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asked Sep 11, 2014 at 5:53
6
You'll want the g modifier for format that drops insignificant zeroes;
>>> "{0:.6g}".format[5.5657188485]
'5.56572'
>>> "{0:.6g}".format[3.539]
'3.539'
Sorry, my update also includes the fact that I am restricted to using Python 2.4.3, which does not have format[] function.
The format specifiers work even without the .format[] function:
>>> for i in a:
... print '%.6g' % [i,]
...
1.01885e+10
5.56572
3.539
22.1523
0
15.9638
0.284024
7.58097
24.3469
Burhan Khalid
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answered Sep 11, 2014 at 5:58
Joachim IsakssonJoachim Isaksson
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3
There is a way to retain trailing zeros so that it consistently shows the number of significant digits. Not exactly what OP wanted, but probably useful to many.
a = [10188469102.605597,5.5657188485,3.539,22.1522612479,0,15.9638450858,0.284024,7.58096703786,24.3469152383]
for i in a:
print["{:#.6g}".format[i]]
Output
1.01885e+10
5.56572
3.53900
22.1523
0.00000
15.9638
0.284024
7.58097
24.3469
Note that this will only work with the format function and not with % operator.
According to the docs:
The
'#'option causes the “alternate form” to be used for the conversion. The alternate form is defined differently for different types. This option is only valid for integer, float, complex and Decimal types.
'g': General format ... insignificant trailing zeros are removed from the significand, and the decimal point is also removed if there are no remaining digits following it, unless the '#' option is used.
answered Apr 29, 2019 at 15:46
jadelordjadelord
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1
try this way
a=[10188469102.605597,5.5657188485,3.539,22.1522612479,0,15.9638450858,0.284024,7.58096703786,24.3469152383]
for i in a:
if i >100:
print '{:.6e}'.format[i]
else:
print '{:.6f}'.format[i]
for lower version of python
for i in a:
if i >100:
print '%6e'%i
else:
print '%6f'%i
output
1.018847e+10
5.565719
3.539000
22.152261
0.000000
15.963845
0.284024
7.580967
24.346915
answered Sep 11, 2014 at 6:11
sundar natarajsundar nataraj
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1